On a solid-state head, the hinged insert/display door behind the glass touches or pushes on the backglass.
Light panel pressing against the backglass
Cause: The hinged door has warped.
Checks
- With the glass in, look for a gap between the door and the glass all the way round.
Fix
- Repair or straighten the door so it no longer presses on the glass; steady pressure can crack the backglass.
Systems
- Williams System 3
- Williams System 4
- Williams System 6 / 6A
- Williams System 7
- Williams System 9
- Williams System 11
- Williams System 11A
- Williams System 11B
- Williams System 11C
- WPC Alpha-Numeric
- WPC Dot Matrix
- WPC Fliptronics
- WPC DCS
- WPC-Security (WPC-S)
- WPC-95
- Bally MPU AS-2518-17
- Bally MPU AS-2518-35
- Stern MPU-100
- Stern MPU-200
- Bally 6803
- Gottlieb System 1
- Gottlieb System 80
- Gottlieb System 80A
- Gottlieb System 80B
- Gottlieb System 3
- Data East CPU Version 1/2
- Data East CPU Version 3
- Data East/Sega CPU Version 3b
- Capcom
Source: Pinball Machine Care & Maintenance, Bernard B. Kamoroff (Bell Springs Pinball Alley)